Curable compositions are utilized for providing high quality, permanent bonding or protection in many different commercial and industrial settings. These compositions are especially useful because of their ability to strongly resist corrosion and adhere to a variety of materials, including metal, glass, plastic, wood and fiber.
Two forms of epoxy-based compositions are commercially available. The first form, one component compositions, are available as rigid epoxy compositions, frozen pre-mix flexible epoxy compositions, and room-temperature stable flexible epoxy compositions. While one component compositions provide the convenience of storage as a single component, they also require elevated curing temperatures. The second form, two component compositions, are stored as two separate components that are mixed just prior to application. Two component compositions overcome the often inconvenient curing requirements of one component compositions since they can be cured at room temperature.
Examples of two component epoxy compositions can be found in:
U.S. Pat. No. 4,728,737 which discloses a two component formulation containing (i) an epoxy plus a polyisocyanate or anhydride and (ii) a mixture of amido amines, primary or secondary amines having tertiary amine groups or ether groups in their backbone and bisphenol A;
U.S. Pat. No. 6,248,204 which discloses a room temperature curable two component formulation of an epoxy resin and a polyether amine-based hardener;
U.S. Pat. No. 7,157,143 which describes a two component epoxy adhesive composition containing an epoxy resin and a curing agent, with each component optionally containing a flexibilizer; and
U.S. Pat. No. 7,834,091 which discloses a two component adhesive composition consisting of two epoxy resins and an amine compound having a molecular weight of less than 450 g/mol.
One drawback to conventional two component epoxy-based compositions containing amine curing agents for curing at ambient conditions is the cured compositions exhibit less than ideal thin-film cure times and pot lives (gelation time). It is therefore an object of the present disclosure to provide a novel two component curable system containing an amine curing agent which provides a relatively fast thin-film cure time in combination with a long pot life.